Incandescent electric lamp



July 28, 1925. 1,547,747

J. C. GROGAN INCANDESCENT ELECTRI C LAMP Filed Jan. 24, 1921 4 OPALGLASS LEARGLASS INVENTOR JACOB GQROQAN ATTORNEY Patented ul 28, 1925.

UNITED STATES PATENT OFFICE "JACOB O. GROGAN, OF NEWARK, NEW JERSEY,ASSIGNOR TO WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA.

INOANDESCENT ELECTRIC LAMP,

Application filed January 24, 1921. Serial No. 489,872.

Tofilkwirom it may concern:

Be it known that I, JAooB G. ,GRocAN, a citizen of the United States,and a resident of Newark, in the county of Essex and State of NewJersey, have invented a new and useful Improvement in IncandescentElectrio Lamps, of which the following is a specification.

My invention relates to improvements in incandescent lamps, particularlyof the miniature type.

Miniature lamps heretofore manufactured for use in the dental andmedical professions have not met requirements chiefly because they havegiven scattered llght of non-uniform intensity. It is an object of thisinvention to meet such requirements by providin a lamp which willpro3ect a sharply efined circular spot of light of unlform intensity.

In the accompanying drawmg F g. 1 s a plan or top view of my lam Flg. 1sa side view; and Fig. 3 is an en arged view, partly in section. 0

Like numerals indicate like parts in the several views.

My lamp includes the usual base 2 having a bulb 3 cemented thereto inthe usual manner. The bulb, as illustrated, is substantially offrusto-conical shape, and the larger end thereof is provided with a lens4, formed as an integral part of the bulb.

The bulb 3 is composed of two layers of glass, as is usual in lamps ofthis class, being formed by fusing a tube of so-called opal glass withinand to a tube of clear glass. The clear or transparent tube 1s of suchgreater length than the opal tube that, when in a plastic state, it maybe molded to close the end of the tube and to form a lens thereon.

In practicing my invention, I form the bulb of frusto-conical shape, theside walls of which are rendered opaque or translucent by the layer 5which is combined with, or fused to, layer 6. My lamp, therefore,differs from previous lamps partly in having side walls so formed anddisposed as to provide a reflecting surface having such relation to theluminous source that the reflecte? ra s will be directed through thelens I an thereby generally improving the optical system. The smallerend of the bulb is secured to the screw plug or base 2.

A filament 7 is mounted upon supports 8 The small size of my lamp andthe fact that'it produces a sharply defined circular spot of light ofuniform intensity make it especially applicable to a variety of uses.

at I claim is: 1. An incandescent electric lamp adapted for theprojection of a concentrated beam of light, comprising a frusto-conical'body having an inner light reflecting layer and an outer transparentlayer fused thereto, a concentrated light source disposed within saidbody, a base at the lower end of the body, a cover for the upper end ofsaid body comprising a continuation of the said transparent layer and alens integral with said cover.

2. An incandescent electric lamp adapted for the projection of aconcentrated beam of light comprising a frusto-conical body having alight source mounted on support members within said body, a bead oflight reflectin material connecting said supporting mem ers, a layer oflight reflecting material upon the surface of said body, a base at thesmaller end of said body, a cover for the upper end thereof and a lensintegral with said cover.

3. An incandescent electric lamp adapted for the projection of aconcentrated beam of light. comprising a frusto-conical body havingalight reflecting inner layer and an outer transparent layer fusedthereto, a

concentrated light source disposed wlthm said body and carried onsupport members, a bead of light reflecting material connect ing saidsupporting members, a base at the smaller end of said body and a coverfor the larger end of said body comprising a con- 'tinuation of one ofsaid layers and a lens integral with said cover.

' In testimony whereof, I have hereunto subscribed my name this 22nd dayof January, 1921.

' JACOB 0.; GROGAN. I

